Waynegs3

So... some of you have been waiting for results from the cam upgrade on the 93 GTS that Dave Lomas has been working on for me. Here is a video of the dyno tuning we did today.
Upgrades are: X pipe, RMB, shark-tuner, elgin grind cams, titanium lifters.
Car is a 5 speed with 104k miles.
Best pull was 314hp corrected for altitude at the rear wheels.

Chuck Schreiber

What was the total gain?
Baseline to what u are pulling now?

andy-gts

are you uber disappointed?

Mongo

Dunno but the thought of cams is giving me flashbacks of tue Dennis K Screamer 5.0, my dream rebuild..

mark kibort

when the holbert car got 320 with stock 85 cams with headers and only 5 liters, I would be disapointed. I know its more streetable, but thats only a muffler difference. take the screens out of the MAF.

RKD in OKC

Kinda difficult to measure gains if you don't have a before to go with the after.

Hilton

314rwhp is about what a stock 5-speed GTS should be pulling - presumably that figure is from before the cams?

What were the base cams used for the regrind? The original GTS ones? Or did you go with an upgrade to S3/GT?

Has the intake been off for knock sensor replacement?

928mac

On a stock 350 chevy you can leave everything the same, install a big cam and get less HP.

Then you add a intake to match the cam, headers to match the intake and a carb to max the intake and gain 70 HP.
Thats the way it goes, . . and the top end increased from 125 mph to 140 mph

Now port and add some extra air (Boost or NOS) 500HP

Waynegs3

Well, there in lie's the kicker. We didn't do a baseline pull before the cam swaps for a number of now forgotten reasons.
I have yet to drive it, to get that feeling, to see if it feels lots faster.
That's coming this next week.

To answer a few comments...
Screen is off MAF. :-)
Yes, they are the GT grind cams, Dave has the specs...
Yes, manifold was off. Several items were R&R or cleaned. Powder coated etc.
We kept putting timing in it till we were getting about 9 knocks on the sharktuner, then backed it off a bit for safety.
Yes, I'd love to boost it... but the 93 comes with the 1R rods, so not great for boosting...
When I drive it, I have raced my buddy in his 99 911. I can pull him slowly every time. This will have to be my baseline result.
Im told that in the real world, S4's can deliver almost equal amounts of horsepower on the dyno. That the GTS's were overstated. 275 RWHP for s4's and 280 RWHP for GTS's. Can anybody out there verify this? So if that's the case, 280 and I pulled 315, that's 35.... pretty expensive 35 ponies.

I spoke to Bill Ball about this, he was a bit surprised too, he suggested we do a compression test to see if there is a lot of carbon built up in the chambers. If so, there is a possibility that its knocking too soon, and as a result we have to take too much timing out of it... (possibly) if that's the case, then a BG flush to clean out carbon, then more timing (possibly)... then more HP? I know its a long shot but I have to keep telling myself that I will be able to take on a new camaro or mustang in the real world race... or at least that was the goal when I started this process... not to sure now.

And yes, I feel like crying....

Lizard928

Wayne,
baseline is everything!
Mark K keeps claiming 320-335 out of his motor, Dennis Koa claims 375ish. But Dennis's before dyno was almost 350. So figure a 25RWHP gain. I personally think that the dyno MK uses is a little optimistic as well. But without going to different dynos it is hard to say. Your 314rwhp on that dyno could be 400 on the dyno Dennis used, and 380 on the one MK uses. It is all relative.

I put down 303RWHP with stock S4 cams, then I put in my big lift cams and got 325rwhp. But I had the cams really advanced for some testing, the flappy had died since the initial run, and I had almost no tuning done. This is a stock S4 motor with an X pipe (home made), and a RMB. After setting the cams to zero, and pulling out the flappy butterfly the car woke up! I havent gotten it onto the dyno yet. But I am predicting 340-350.
Again, bone stock internals with 230,000 MILES.

pcar928fan

I can confirm this...sort of. On different days but the same dyno and same tech running it...

My '88 S4 auto pulled something like 263/265 (RW - Hp/Tq)
My '92 and '94 GTS Auto's did about 285/305

The auto sucks a TON of RW Hp/Tq out of these cars that you should not lose on a 5spd car.

There was a VERY, VERY well sorted 86.5 5spd car that same day that pulled almost the exact same numbers as my GTS's did! Stunning really! Like I said, it was fully sorted with some exhaust work and injectors, etc, but nothing like open engine work. Just everything optimized and some good exhaust stuff done to it.

Based on my numbers (other than questioning what is the proper correction to figure...maybe 20% for driveline loss) my cars are performing about like they should. BTW, they are all bone stock except RMB's on S4 and '92 GTS. My numbers support the factory claimed difference between the S4 and GTS (ie. ~25HP and ~50Tq, again once driveline losses are calculated).

I lust after Jim M. and Roger's GTS numbers though! Those guys cars are REALLY GETTING IT DONE!

SeanR

We've not even finished with the tuning or done any dyno runs with the new cams. That should be coming soon since we've got a new local dyno guy 5 minutes from my place.

pcar928fan

SO he was making GREAT power with the old cams right? Can I buy those for the '92?! Guessing they are already spoken for!

SeanR

In Jims they are just GT cams, Rogers has modified S3's. So yea, he was making great power before hand but those were with normal GTS cams. Now it is just a beast.

GregBBRD

Finally...another voice of reason.

Most of the rear wheel dyno results that are posted are total BS numbers.

Thank you, Colin!